How to fix monitor flickering?

Hi,
I have a common LCD monitor with max refresh rate of 60Hertz (that is being used).It is 6 years old. It uses recomended refresh rate and its driver is updated. During this year, it has specific flickering problems. When I turn the computer on, the monitor flickers for about 30 mins. After that, it stabilizes, works as it should work. Also, when the dark pixels cover around 80% of the screen (longer than 15 mins), my monitor starts flickering again. Bright pixels seam to be bringing it back to life. Since it stabilizes after the first 30 mins of its usage, the only thing I could think of is that it has some energy problems (heating, energy consuption) . Also, maybe the bright pixels are more "demanding" and they make the monitor consume more energy and work properly (my theory). I want to know if there are some other ways to make the monitor consume more energy or heat up faster (if possible). Thank you.

p.s. Tell me if I m on the right track, I m not a computer scientist, I just wanna solve this thing and get done with it...